Welcome to the forum
1. Obviously make sure the slide out(s) move freely all the way in and out. A bit of jerking may happen - I have one slide that does this
2. Make sure all of the seals are in good shape around the slide. There are "wipers" on the outside and just under them are Bulb seals.
Unless there are problems with leakage there shouldn't be any other issues. I would check the roof though. Also check that all of the appliances and so on work, Fridge, Furnace, Microwave, vents, range, AC, water pump. My nephew has that model, but the 2019 version. The only issue he had was the fridge. Good luck and enjoy.